The influence of the dendritic structure on the γ/γ′-lattice misfit in the single-crystal nickel-base superalloy CMSX-4

The γ/γ′-lattice misfit was measured locally by X-ray diffraction in the rhenium-containing single-crystal nickel-base superalloy CMSX-4. Different sections of a single crystal casting and positions in the dendritic structure have been analyzed. A remarkable difference of the misfit caused by segregation of refractory elements was found between the dendrite center and periphery. Problems of measurement and characterization of the γ/γ′-lattice misfit in superalloys of new generations with a high refractory element level are discussed.